As of 2019, the record for a Big Year in the US is 836 species of birds.
The average cost of a big year is estimated between $30,000 and $40,000. The cost could be higher depending on travel costs to chase rare bird sightings anywhere in the country at any time of the year.
Jack Black's fall at Attu Island was unscripted.
Steve Martin wrote much of the music in his 2011 album, "Rare Bird Alert" (Steve Martin and the Steep Canyon Rangers), while on the set for this movie.
In the scene on the boat when Bostick (Owen Wilson) gets angry that Annie wants to watch whales instead of birds, he exclaims that she's "crazier than a road lizard". This is a phrase Owen Wilson uses in several of his other movies including Shanghai Noon and Night at the Museum.